Press, particularly for photographic purposes



y 1945- i A. w. PERRY 2,375,491

PRESS, PARTICULARLY FOR PHOTOGRAPHIC PURPOSES FiledDec. 18, 1943 2Sheets-Sheet Andrew W Penliven for A I Ma /M41911- M y 8, 1945- A. w.PERRY PRESS, PARTICULARLY FOR PHOTOGRAPHIC PURPOSES Filed Dec. 18, 19432 Sheets-Sheet 2 u %m w @w wi v m; W WW1 M 0. M4

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Patented May 8, 1945 PRESS, PARTICULARLY FOR PHOTO- 1 GRAPHIC PURPOSESAndrew William Perry, Harrow, England, as-

signor to Pictorial Machinery Limited, London, England, a Britishcompany Application December 18, 1943, Serial No. 514,753 In GreatBritain November 24, 1942 3 Claims.

This invention relates to presses, particularly in the form of contactprinting frames for photographic purposes, of the type (hereinafterreferred to as the type described) comprising two press members havingflat faces of extended form, whereof one is movable bodily towards andaway from the second, and pressure means that is operatively connectedwith the second press member and is arranged to force the movable pressmember towards the second press member.

It is an object of the present invention to provide an improved press ofthe type described having pressure means so constructed and arranged asto exert on sheet material arranged between the two press members, auniform pressure in a direction normal to the sheet material.

According to the invention there is provided a press of the typedescribed, wherein the pressure means comprises a support that isadapted to be fixed in relation to the second press memher, a pluralityof pressure members that are rotatably mounted in spaced relation on thesup port, and are arranged to impart pressure to the movable pressmember at a plurality of positions spaced apart one from another formoving it towards the second press member, and actuating means foractuating the pressure members in unison. Owing to the pressure beingapplied to the movable press member at a number of situa tions on itsouter surface, a uniform pressure is applied to the sheet material overits entire area.

The pressure members are preferably mounted to rotate in relation totheir support.

Such rotary pressure members may be rotat able about axes that lietransversely of the direction of movement of the movable press member.

Conveniently, a plurality of spindles are journalled in bearings on thesupport, each of which spindles carries two pressure members arranged inspaced relation along it, for example at its ends, and an actuatingmember operatively connected to the spindles is arranged to rotate themin unison.

In a preferred constructioma plurality of pairs of brackets are mountedin spaced relation on the'movable pressmember, which brackets makesliding engagement with the support, and the pressure members arearranged to coact with, and exert their thrust through the brackets.

Other features of the invention relating to the mounting of the movablepress member on the hinged support will be described hereinafter.

One embodiment of the invention is diagrammatically illustrated by wayof example in the accompanying drawings, wherein- Figure 1 is aperspective view showing one form of press constituting a printing frameaccording to the invention,

Figure 2 is a side elevation thereof,

Figure 3 is a front end elevation,

Like reference characters designate like parts in all the views.

Referring to the drawings, one method of carrying the invention intopractice will now be described by way of example, and not by way oflimitation, with reference to a pressure-contact printing frame used forphotographic purposes. A box it for containing a source of light, e. g.,one or more electric lamps, not shown, has at the top thereof a sheet oftransparent material I2, preferably glass, constituting a fixed pressmemher. A movable press member l4 constituted by a slab of wood having asheet of soft material [6, e. g., felt, at its under. side is mounted,as described hereinafter, so as to swing from a vertical inoperativeposition, in which it permits a photographic negative to be placed onthe glass sheet 12, and a sheet of light sensitive paper to be placed onthe negative, to an operative horizontal position in which it liesadjacent to the top of the paper sheet.

In order to press the movable press member towards the glass plate,pressure means is provided comprising four L-shaped brackets 2!, 22, 23,24, fixed by their horizontal limbs to the top of the woodslab I4. Thesebrackets are arranged in two pairs 2!, 22 and 23, 24 arranged spacedapart at opposite sides of the centre of the slab I4, and each verticallimb has in it a vertical slot 26. A support designated generally 28, inthe form of an oblong metal frame having a front end member 33, two sidemembers 3|, 32, and a counterweight 33 at its rear end, has pins 34 atits opposite sides that take each into a slot 26 in the brackets topermit vertical movement of the support. The rear end portion of thisoblong frame 28 is hinged at 35 to the rear side of the box to which theslab of wood is hinged, and its opposite end is provided with readilydetachable means for securing it to the front side 38 of the box whenpressure is to be applied. As illustrated, the detachable means isconstituted by a pivoted fastener 40 in the form of a loop that iscarried b the front end member 3!) of the frame 2.8 and is arranged toengage a pin 42 fixed on the front of the box It. This oblong frame 28carries four bearing brackets 44, 45, 46, 41, one adjacent tensionsprings 68, 69, 10, H is two-fold:

to each slotted limb of the L-shaped brackets 2|, 22, 23, 24, and twoparallel spindles 48, '50 are journalled respectively in the bearingbrackets 44, 45 and the bearing brackets 46, 41. These spindles 48, 50carry each two press members 52, 54 and 56, 58, respectively in the formof eccentrics, cams or the like, one on each end, each of which pressmembers lies at the top of one of the slotted limbs of the L-shapedbrackets 2|, 22, 23, 24. Actuating means for operating these eccentrics,or cams, comprises two arms 60,132, fixed at one end respectively to themiddle of the spindles 48 and 50, the other ends of which armspivo-tally carry an actuating member 64 in the form of a T-shaped rod,whereof thecross-piece 66 constitutes a hand-grip. Four tension coilsprings 68, 69, 10, TI are provided, one adjacent to each bearingbracket 44, 45, 46, '41; the lower end of each of these springs isanchored to the horizontal limb of the adjacent L-shaped brackets 2|,22, 23, "24, and itsupper end is anchored to a pin 12 on the adjacentbearing bracket. The wood slab I4 is thus resiliently mounted on itssupporting hinged frame 28 and is arranged to float in relation thereto.The function of the (1) to maintain contact between the top pressurefaces of the slotted limbs of the L-shaped brackets and the eccentricsthereon, thereby steadying the floating movable press member constitutedby the wood slab, and (2) to keep this press member from contact withthe lower fixed glass before the pressure means is actuated by theactuating member 64, as it is important that the top press member shallnot touch the lower fixed press 1 member when being swung down into itsoperative position.

When pressure is to be applied to the sheet material in the contactprinting frame, and the oblong frame of the pressure-imparting means hasbeen fastened in its operative position with the movable press membersituated just above the sheet material, it is only necessary manually topull the actuating member '64, rotate the two spindles 4B, 50 and theireccentrics or cams in unison, whereby pressure is imparted by themthrough the vertical slotted limbs of the L-shaped brackets to the slabof wood, which is thereby moved bodily parallel to itself and presseduniformly against the sheet material on the glass below it. In order toreleasethe printing frame for removal of thesheet material, it is onlynecessary to move the actuating member 64 in the .opposite direction.release the fastening means 40 of the oblong metal frame 28 and swingthe latter with the movable press member into a vertical position.

Various modifications may be made in the details of constructiondescribed above without departing from the invention. For example, thepressure means may comprise more than four brackets 2 I, 22, 23, 24fixed to the top of the wood slab to give pressure points at from 3 in.to 24 in. centres or more as required. Similarly, the oblong metal frame28 may carry more than four bearing brackets 44, 45, 46, 41 and theremaybe more than two parallel spindles 48, 50 journalled in them. Again,there may bemore than four of said tension coil springs 68, 69, 10, H.Further,

the metal oblong frame 28 may carry two feet I4 at or near its front endfor bearing on the top of the box It). Also, in some cases, thetransparent sheet of a printing frame may constitute the movable pressmember, in which case the fixed press member will be constituted byopaque mate rial, e. g., wood.

I claim:

1. A press comprising two press members having fiat faces of extendedform whereof one is movable bodily towards and away from the second, andpressure means that is operatively connected with the second pressmember and is arranged to force the movable press member towards thesecond press member, which pressure means comprises a support that isadapted to be fixed in relation to the second press member, a pluralityof pairs of brackets mounted in spaced relation on the movable pressmember adjacent to the support, a plurality of rotary eccentric pres--sure members arranged in pairs, one pair allotted to each pair ofbrackets, for imparting pressure through the brackets to the movablepress memher, and actuating means for actuating the 'pres sure membersin unison.

2. A press comprising two press members having flat faces of extendedform, whereof one is slot mounted in spaced relation on the movablepress member, a plurality of pressure members, oneallotted to eachbracket, for imparting pressure to the movable press member, actuatingmeans for actuating the pressure members in unison, which support has aplurality of fins extending each into a slot in a bracket, and aplurality of springs mounted in spaced relation on the support forresiliently supporting the movable press member.

3. A press comprising two press members having fiat faces of extendedform, whereof one is movable bodily towards and away from the second,and pressure means that is operatively connected with the second pressmember and is arranged to force the movable press member towards thesecond press member, which pressure means comprises a support that isadapted to be fixed in relation to the second press member, a pluralityof brackets each having a Vertical guide slot mounted in spaced relationon the movable press member, a plurality of spindles journalled on thesupport, each of which spindles carries two pressure members in the formof eccentrics arranged in spaced relation along it, and allotted each toone of said brackets, a manual actuating member that is operativelyconnected to the spindles and is arranged to rotate them in unison.which support has a plurality of pins extending each into a slot in abracket, and a plurality of springs mounted on the support, one adjacentto each bracket, for resiliently supporting the movable press member.

ANDREW WILLIAM PERRY.

